Discipline: Ecology Environmental and Earth Sciences
Arrieyana Cartier - Virginia State Unviersity
Co-Author(s): Mina Williams and Shobha Sriharan, Virginia State University Jason Adolf, University of Hawai'i at Hilo
Hilo Bay is located in Hilo, Hawai’i is an estuary system with freshwater entering from the rivers and groundwater and saltwater entering from the ocean. Heavy precipitation causes flooding of the watershed and a migration of watershed sediments into Hilo Bay through the Wailoa and Wailuku River. The presence of a three mile break wall affects the circulation in the bay causing water and pollutants to remain in the bay for longer than normal ocean currents would permit. Our hypothesis was that the presence of the town contributed to anthropogenic impacts on Hilo Bay which negatively affected the water quality. Three transects were performed in Hilo Bay with data collected every 500 m for 5 km for two of the transects and data collected every 500 m for 15 km for one transect on three separate days. At each site a 1 L sample of water was collected in a brown bottle from the top meter of the ocean and stored in a cooler. An YSI probe was placed in the top meter of the ocean to collect data on the salinity, temperature, and dissolved oxygen at each sampling station. Measurements were taken on the secchi depth, turbidity, and chlorophyll α. A linear regression and descriptive statistics were performed on the data to find statistically significant trends. As the distance from the shore increased thee turbidity decreased and salinity increased. The highest turbidity values were recorded closer to the mouth to shore. The river provides a vehicle for sediment to enter Hilo Bay causing high turbidity. As the distance from shore increases the water becomes much rougher allowing for greater dilution of sediments. Several peaks were observed which corresponded to sampling stations from where river mouths connect with the ocean. We also found that as the salinity increased chlorophyll α decreased. Turbidity decreased and secchi depth were found to be inversely proportional. There was large variation between three transects with respect to the same parameter. More data is needed to make a definitive conclusion as to if anthropogenic impacts are affecting Hilo Bay. Abiotic factors could have also have affected the data collected as there was high variation between the data Hilo Bay. Further research that is to be done is to increase the number of transects completed as well as test the water for markers of pollution.
Funder Acknowledgement(s): The author acknowledges NSF HBCU UP Supplement Grant for summer internship.
Faculty Advisor: Shobha Sriharan,